Anisotropic water diffusion in white and gray matter of the neonatal piglet brain before and after transient hypoxia-ischaemia

Magn Reson Imaging. 1997;15(4):433-40. doi: 10.1016/s0730-725x(96)00378-5.


Measurements of tissue water apparent diffusion coefficient (ADC) performed with diffusion sensitization applied separately along the x, y, and z axes revealed significant diffusion anisotropy in both cerebral white and gray matter in six newborn (< 24 h old) piglets. Mean baseline white matter ADC for a particular region of interest was 125.8% (SD 32.0%; p < .001) greater when the diffusion gradients were applied along the y axis as compared to along the x. For the cortical gray matter region considered, the situation was reversed, the mean ADC value measured along x exceeding that along y by 15.2% (SD 6.1%; p < .01). Forty-three hours subsequent to a transient cerebral hypoxic-ischaemic insult, phosphorous MRS measurements indicated that the animals had suffered severe secondary cerebral energy failure. This was accompanied by a significant (p < .01) decrease in the white matter anisotropy, such that the mean y direction ADC now exceeded that along the x by only 70.9% (SD 29.4%; p < .03). There was no change in the gray matter anisotropy. The average of the ADC values measured in the x, y, and z directions had decreased by 35.3% (SD 18.5%; p < .01) in white matter and 31.4% (SD 21.9%; p < .05) in cortical gray matter. Diffusion anisotropy measurements may provide additional information useful in the characterisation of hypoxic-ischaemic injury in the neonatal brain, and must be considered if tissue water ADC values are to be unambiguously interpreted in this context.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Anisotropy
  • Asphyxia Neonatorum / metabolism
  • Asphyxia Neonatorum / pathology
  • Brain / metabolism*
  • Brain / pathology
  • Disease Models, Animal
  • Energy Metabolism / physiology*
  • Humans
  • Hypoxia, Brain / metabolism*
  • Hypoxia, Brain / pathology
  • Infant, Newborn
  • Ischemic Attack, Transient / metabolism*
  • Ischemic Attack, Transient / pathology
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Spectroscopy
  • Swine